JPS622471A - Method for cooling battery of electric vehicle - Google Patents

Abstract

PURPOSE:To prevent the rise in the temperature of a battery for an electric vehicle, by supplying a liquid coolant to a coolant evaporation layer, and sending a natural convection wind or a fan wind to promote the evaporation of the liquid coolant. CONSTITUTION:A coolant evaporation layer 2 is made of a porous material. A coolant gutter 3 surrounds the bottom of the outside wall of the body of a battery or an electrolyte vessel 1. The bottom of the coolant evaporation layer 2 is located in the coolant gutter 3 to such up a coolant by a capillary action. A liquid coolant filled in a liquid coolant vessel 4 is supplied to the coolant gutter 3 through a conduit 4'. As the liquid coolant is being supplied to the battery body or the electrolyte vessel 1, a natural convention wind caused by the movement of a vehicle or a fan wind is applied to the peripheral portion of the battery body or the electrolyte vessel to promote the evaporation of the liquid coolant. Latent heat is thus absorbed to cool the the outside wall of the battery body or the electrolyte vessel 1.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of Application The present invention relates to a method for cooling a battery, such as a zinc-bromine secondary battery, when the battery is used as a power source for an electric vehicle or the like. .

B6 Summary of the Invention The present invention is a cooling method that is used to maintain a power supply battery of an electric vehicle such as an electric vehicle at the optimal temperature for battery operation from natural temperature rise during high temperatures in summer. This invention relates to a method of cooling a battery, in which a water-absorbing porous material is attached to the outer wall surface of both or both of the above, and water is supplied to the material while IQK wind is sent around the material and the battery is cooled by the heat of vaporization of the water.

C6 Conventional technology Zinc-bromine secondary batteries are being considered for use as energy storage secondary batteries because they have high energy density, high battery efficiency, and are abundant in zinc and bromine as active materials and are inexpensive. However, demand is also expected as a power source for electric vehicles such as electric cars.

However, it is well known that batteries generally become less efficient when exposed to high temperatures, increase side reactions such as gas generation, and shorten their lifespan due to moisture evaporation.0 Zinc-bromine batteries If the temperature exceeds 40° C., the efficiency decreases, so the optimum operating temperature is relatively low, and this cooling method may pose a problem if it is put into practical use.

Problems to be solved by the D0 invention - The environment in which motor vehicles are used is severely affected by climatic conditions, such as exposure to direct sunlight in the summer and reflection of road surfaces, which can exceed temperatures above 0°C. is not rare. If the battery temperature rises in such an environment, not only will self-discharge of the battery increase and the distance it can travel on a single charge will decrease;
There have been problems such as safety problems due to the increase in vapor pressure of bromine, and the acceleration of the action of bromine on the plastics etc. that make up the electrode and its frame, shortening the useful life of the battery.

In addition, the installation location of batteries in electric vehicles is limited to ensure space for passengers and cargo, and because the electrolyte is highly corrosive, conventional methods such as air cooling or water cooling using radiators are used. Common cooling means are not available.

The present invention has been made to solve the problem of cooling the batteries for electric vehicles as described above.Means for solving the OE6 problems The present invention solves the difficult problems in the batteries for electric vehicles as described above. As a cooling means, liquid coolant such as water is applied to the outer wall of either or both of the battery body and its electrolyte tank by capillary action using woven or non-woven fabrics such as gauze, felt, unglazed ceramic plates, porous plastic sheets, etc. In order to provide a refrigerant evaporation layer in which the liquid refrigerant permeates and evaporates the liquid refrigerant from a large surface area, and to supply the liquid refrigerant to this refrigerant evaporation layer, and to promote the evaporation of the liquid refrigerant around the battery body and the electrolyte tank. By blowing air through natural convection or a fan, the temperature rise of the electric vehicle battery, which is the object of the present invention, is prevented.

F0 Effect According to the battery cooling method of the present invention described above, the outer wall surface of either the battery body or the electrolyte tank or both is constantly cooled by the evaporation of the liquid refrigerant supplied to the refrigerant evaporation layer on that surface. , the temperature rise of the battery and electrolyte can be suppressed.

G0 Embodiment of the invention FIG. 1 is a schematic cross-sectional view showing an embodiment of the battery cooling method of the invention! The code (1) in the 1% diagram is the battery body or electrolyte tank. However, if this is a battery body, there are positive and negative polarity chambers in which the positive and negative electrodes are placed, separated by a diaphragm, and each of these positive and negative polarity chambers contains a separate electrolyte solution. The electrolyte is circulated from the tank, and if this is an electrolyte tank, the VC
The battery is charged with the electrolyte solution being completely filled and the electrolyte being circulated as described above through the piping system provided between the battery and the battery body.

Assume that a discharge occurs. (2) is a refrigerant evaporation layer attached to the outer wall surface of the battery body or electrolyte tank (1) by an appropriate means such as direct attachment, and this refrigerant evaporation layer (
2; may be made of woven or non-woven fabrics such as gauze, felt, cloth, valve layers, porous boards, porous asbestos boards, porous ceramics, open-cell plastics, porous plastics, etc. (3) is a refrigerant gutter, which is provided at 5 to surround the lower end of the outer wall surface of the battery body or electrolyte tank (1), and in which the lower end of the refrigerant evaporation layer (2) is provided. The refrigerant is housed in such a way that the refrigerant can be drawn up by capillary action. (41 is a liquid refrigerant tank, (4I) is its conduit, and the liquid refrigerant filled with the liquid refrigerant tank (4)K is supplied to the refrigerant gutter (3) through the conduit (41). (5) is the conduit (4
This is a liquid level adjustment device provided between the refrigerant gutter (3) and the refrigerant gutter (3) to adjust the amount of liquid refrigerant supplied to the refrigerant gutter (3). In addition, when the refrigerant evaporation layer (2) is formed of foamed plastic or porous plastic, when molding the battery body or the case of the electrolyte tank (1) from plastic, a special mold is used for simultaneous molding. Moreover, since the refrigerant layer (2) can be provided on the outer wall surface at the same time, it does not take much time to manufacture and is suitable for mass production.

While supplying liquid refrigerant to either or both of the battery body and the electrolyte tank equipped with the cooling means described above, natural convection of wind from the vehicle running or wind from a fan is sent around them. Evaporation is promoted, and as a result, latent heat is removed and the outer surface of the battery body or electrolyte tank (1) is cooled.

As described in detail in the H1 invention, according to the battery cooling power method of the present invention, it is possible to suppress the rise in temperature of batteries used as a power source for electric vehicles due to temperature rises such as in summer or due to narrow installation locations. This can increase battery efficiency and extend its service life. Further, this cooling method has excellent effects when a zinc-bromine secondary battery is used as the power source.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional explanatory diagram showing an embodiment of the battery cooling method of the present invention. Symbols in the figure (11 is the battery body or electrolyte tank, (2) is the refrigerant evaporation layer, (3) is the refrigerant gutter, (4) is the liquid refrigerant tank, (4)
1) is a conduit, and (5) is a liquid level adjustment device. Agent Patent Attorney Tadashi Sato Figure 1 1-Den 2 Hoiho or Electrolytic Layer 1 So 2; 4': Guide 5: Performance familiarization device

Claims (1)

[Claims] A refrigerant evaporation layer for evaporating a liquid refrigerant made of a porous material is provided on the outer wall surface of either or both of the battery main body and its electrolyte tank, and the liquid refrigerant is supplied to the refrigerant evaporation layer, and the battery main body and the electrolyte tank A method for cooling a battery for an electric vehicle, characterized by sending air around the battery by natural convection or by a fan.